\Header{strsplit}{Split the Elements of a Character Vector}
\keyword{character}{strsplit}
\begin{Description}\relax
Split the elements of a character vector \code{x} into substrings
according to the presence of substring \code{split} within them.\end{Description}
\begin{Usage}
\begin{verbatim}strsplit(x, split, extended = TRUE)\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] character vector, to be split.
\item[\code{split}] character vector containing a regular expression to use
as \dQuote{split}.  If empty matches occur, in particular if \code{split}
has length 0, \code{x} is split into single characters.  If
\code{split} has length greater than 1, it is re-cycled along \code{x}.
\item[\code{extended}] if \code{TRUE}, extended regular expression matching
is used, and if \code{FALSE} basic regular expressions are used.
\end{ldescription}
\end{Arguments}
\begin{Value}
A list of length \code{length(x)} the \code{i}-th element of which
contains the vector of splits of \code{x[i]}.\end{Value}
\begin{SeeAlso}\relax
\code{\Link{paste}} for the reverse,
\code{\Link{grep}} and \code{\Link{sub}} for string search and
manipulation; further \code{\Link{nchar}}, \code{\Link{substr}}.\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
noquote(strsplit("A text I want to display with spaces", NULL)[[1]])

x <- c(as = "asfef", qu = "qwerty", "yuiop[", "b", "stuff.blah.yech")
# split x on the letter e
strsplit(x,"e")

unlist(strsplit("a.b.c", "."))
## [1] "" "" "" "" ""
## Note that 'split' is a regexp!
## If you really want to split on '.', use
unlist(strsplit("a.b.c", "\\."))
## [1] "a" "b" "c"

## a useful function: rev() for strings
strReverse <- function(x)
        sapply(lapply(strsplit(x,NULL), rev), paste, collapse="")
strReverse(c("abc", "Statistics"))

a <- readLines(file.path(R.home(),"AUTHORS"))[-(1:8)]
a <- a[(0:2)-length(a)]
sub("\t.*","", a)
strReverse(sub(" .*","", a))
\end{ExampleCode}
\end{Examples}

